PhD Chemistry (Analytical) Area of Research Interest: Muhammad Mushtaq PhD Chemistry (Analytical) Area of Research Interest: Hplc-based METHOD development and validation, revalorization of under-utilized agricultural-waste streams into phenolics of high antioxidant potential Development of highly sensitive and selective molecule counting machines Teaching Interests: Analytical Chemistry, Physical Chemistry Title of talk: Vibrational changes during water dynamics: AN evitable and non-destructive diagnostic tool

Water: Universal solvent and main absorber Background: Water: A Universal solvent and main absorber of sunlight Quickly absorbs in UV, Visible, Infrared and Microwave Water molecule may vibrate in number of ways (very complex and phase dependent) IR frequencies change with intermolecular integrity Non-destructive profiling with zero or little sample preparation More suitable for living organisms

Fundamental vibrations in water ν1,O-H symmetric stretching 3657 cm−1         ν2, H-O-H bending 1595 cm−1                                      ν3, O-H asymmetric stretching 3756 cm−1 In the gas phase all three bands show extensive rotational fine structure There is no rotational in liquid and solid but the absorption bands are broader because of hydrogen bonding a 3rd overtone falls visible region (responsible for blue color of water) IR cuvettes made of substances which are water-insoluble (calcium fluoride). This difficulty has been overwhelmed by an attenuated total reflectance (ATR) ν1,O-H symmetric stretching  3450   cm−1 ν2, H-O-H bending 1640 cm−1                                      ν3, O-H asymmetric stretching 3615 cm−1 ν1,O-H symmetric stretching 3400 cm−1         ν2, H-O-H bending 1620 cm−1                                      ν3, O-H asymmetric stretching 3220 cm−1

ATR-FTIR of Water Dynamics The stretching band in liquid water is shifted to a lower frequency (v3, 3490 cm-1 and v1, 3280 cm-1 and the bending frequency increased (v2, 1644 cm-1 by hydrogen bonding. An increase in the strength of hydrogen bonding typically causes red-shift with greatly increased intensity Rotations in the liquid phase are totally dominated by hydrogen bonding. Libration is a type of reciprocating motion in which an object with a nearly fixed orientation repeatedly rotates slightly back and forth. As water molecule is attracted to neighboring molecules, so it has a preferred orientation and cannot freely rotate. Of course, when the neighboring molecules move around and the preferred orientation changes which are measureable in an infrared absorption spectrum

ATR-FTIR of Water Dynamics The stretching band in liquid water is shifted to a lower frequency (v3, 3490 cm-1 and v1, 3280 cm-1 and the bending frequency increased (v2, 1644 cm-1 by hydrogen bonding. An increase in the strength of hydrogen bonding typically causes red-shift with greatly increased intensity Rotations in the liquid phase are totally dominated by hydrogen bonding. Libration is a type of reciprocating motion in which an object with a nearly fixed orientation repeatedly rotates slightly back and forth. As water molecule is attracted to neighboring molecules, so it has a preferred orientation and cannot freely rotate. Of course, when the neighboring molecules move around and the preferred orientation changes which are measureable in an infrared absorption spectrum

Effect of temperature and Pressure on ATR-FTIR bands of Water Recent work, using attenuated total reflectance (ATR) infrared spectroscopy, shows that H2O observes isobestic points at 600, 1600, 1680 and 3550 cm-1 Increasing the pressure on water decreases the O····O distances which increases the covalent O-H distances and lowers their stretch frequency. An increase in pressure also causes a reduction in long, weak or broken bonds and an increase in bent and short, strong hydrogen bonds. Of course, when the neighboring molecules move around and the preferred orientation changes which are measureable in an infrared absorption spectrum

Variation in IR regions of water Especially near IR vary With temperature and Chemical composition This provides basis for A non-destructive Composition analysis Comparison of affected cites with healthy one Structural and conformation variation in protein integrity of biological systems Adulteration/contamination studies Understanding the role of water in biological system The near-infrared (NIR) bands (at about λ 970-1940 nm) are suited to rapid non-destructive water determination * The whole scenario demands that Intensity of the OH Stretching Band of Liquid Water should Revisited

A groundbreaking story A groundbreaking invention in this context has been reported on June 29, 2017 by Refael Minnes of Ariel University, Ariel, Israel (nature.com) Who applied ATR-FTIR to distinguish between melanoma cells with a different metastatic potential. The methodology applied involved the investigation of intermolecular structure of water/dynamics and hydration level of cells following ATR-FTIR Water in the biological system is present either as Low Density Water (H-bond with water molecules) or High Density Water (H-bond with other biological molecules) It is understood that molecular LDW (3200 cm-1) and HDW (3400 cm-1) would differs in stretching vibrations A significant spectral difference was observed between the cells of various metastatic states

Applications/Prospectus Hyperspectral imaging is an emerging and rapid technique for nondestructive food analysis This techniques involve the processing of either the visible-short near-infrared (vis-NIR; 400−1000 nm) or near infrared (NIR; 1000−1700 nm) spectral data In another report Near Infrared Spectroscopy (NIRS) was used to Analyze Phenolic Compounds in Plants Non-ionising IR thermal imaging has many advantages. Although not used routinely as a diagnostic clinical tool, it does have potential as a future imaging modality provided that image analysis can be developed to provide reliable routes to interpretation, assessment and diagnosis in medicine